检索结果-南通市图书馆

Computation of Design Load and Motion for Floating Structures Navigating in Waves

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean Engineering 1999年第1期14卷 93-100页

作者： Wang, YY zhu, RC Miao, j Dalian Univ Technol Sch Naval Architecture & Marine Engn Dalian 116024 Peoples R China

Analytical and numerical investigation is made of the source potential for-floating structure with forward speed in waves. A particular form is selected for numerical applications, where the double integral of the Green function is transformed into the single one and the oscillation characteristics for integrands in the specific computation domain are treated numerically. A comparison of calculated examples with published data is given and it shows that the numerical simulation is satisfactory and the accuracy is adequate to engineering application.

关键词： floating structure Green function ship motion source distribution

Novel method for random vibration analysis of single-degree-of-freedom vibroimpact systems with bilateral barriers

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2019年第12期40卷 1759-1776页

作者： Lincong CHEN Haisheng zhu j.Q.SUN College of Civil Engineering Huaqiao UniversityXiamen 361021Fujian ProvinceChina School of Engineering University of CaliforniaMercedCA 95343U.S.A

The vibroimpact systems with bilateral barriers are often encountered in ***,the dynamics of the vibroimpact system with bilateral barriers is full of *** closed-form solutions were *** this paper,we propose a novel method for random vibration analysis of single-degree-of-freedom(SDOF)vibroim-pact systems with bilateral barriers under Gaussian white noise excitations.A periodic approximate transformation is employed to convert the equations of the motion to a con-tinuous *** probabilistic description of the system is subsequently defined through the corresponding Fokker-Planck-Kolmogorov(FPK)*** closed-form station-ary probability density function(PDF)of the response is obtained by solving the reduced FPK equation and using the proposed iterative method of weighted residue together with the concepts of the circulatory probability flow and the potential probability ***,the versatility of the proposed approach is demonstrated by its application to two typical *** that the solution obtained by using the proposed method can be used as the benchmark to examine the accuracy of approximate solutions obtained by other methods.

关键词： bilateral barrier vibroimpact system weighted residue method iterative random vibration

Effect of carrier gases on the entrainment defects within AZ91 alloy castings

在线全文

学校读者我要写书评

暂无评论

journal of Magnesium and Alloys 2022年第1期10卷 142-159页

作者： Tian Li j.M.T.Davies Xiangzhen zhu University of Birmingham Birmingham 8152TTUnited Kingdom Grainger and Worrall Ltd Bridgnorth WV155HPUnited Kingdom Brunel Centre for Advanced Solidification Technology Brunel University LondonKingston LnLondonUxbridge UB83PHUnited Kingdom

An entrainment defect(also known as a double oxide film defect or bifilm) acts a void containing an entrapped gas when submerged into a light-alloy melt, thus reducing the quality and reproducibility of the final castings. Previous publications, carried out with Al-alloy castings, reported that this trapped gas could be subsequently consumed by the reaction with the surrounding melt, thus reducing the void volume and negative effect of entrainment defects. Compared with Al-alloys, the entrapped gas within Mg-alloy might be more efficiently consumed due to the relatively high reactivity of magnesium. However, research into the entrainment defects within Mg alloys has been significantly limited. In the present work, AZ91 alloy castings were produced under different carrier gas atmospheres(i.e., SF6/CO2, SF6/air).The evolution processes of the entrainment defects contained in AZ91 alloy were suggested according to the microstructure inspections and thermodynamic calculations. The defects formed in the different atmospheres have a similar sandwich-like structure, but their oxide films contained different combinations of compounds. The use of carrier gases, which were associated with different entrained-gas consumption rates, affected the reproducibility of AZ91 castings.

关键词： Magnesium alloy Casting Oxide film,Bifilm,Entrainment defect,Reproducibility

INTERFACIAL DEBONDING OF FRC UNDER CYCLIC LOADING

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 327-330页

作者： Q.j.zhu Y.H.Chen j.Chen Department of Civil Engineering Hebei Institute of Technology Tangshan 063009 China School of Civil Engineering Beijing Jiaotong University Beijing 100044 ChinaDepartment of Civil Engineering Hebei Institute of Technology Tangshan 063009 China

With the increasingly use of FRC (fiber-reinforced composite) in urban lifelines, me-chanical properties investigation is very important for disaster resistance, especiallythe investigation of fatigue properties. Based on the shear-lag model, an usual com-posite model under cyclic loading is established. According to the Paris formula, therelationship between interfacial fatigue parameters and the number of cycles is ob-tained under the cyclic loading. Interfocial fatigue properties of this model and thegrowth of the interfacial fatigue crack are analyzed. And the Poisson ratio is consid-ered also.

关键词： interfacial debonding fiber matrix cyclic loading crack growth

Ab initio STUDIES ON MAGNETISM OF 3d TRANSITION METAL DIMERS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2007年第5期20卷 341-346页

作者： j.H. Gu Z.L. zhu School of Physical Engineering and Material Physics Laboratory Zhengzhou University Zhengzhou 450052 China

Ab initio calculations with the self-consistent full-potential linearized augmented-plane-wave method （FLAPW）, under generalized gradient approximation, have been carried out to describe the electronic and magnetic properties of 3d transition metal dimers. It predicted the antiferromagneticity of Cr2 and ferromagneticity of other species. The Mn2 dimer was shown to be ferromagnetic coupling with a local magnetic moment of 5μB. retaining the value of its free atom state. The V2 and Ni2 exhibited low spin-polarization with local magnetic moment of only 1μB per atom. On the other hand, Fe2 and Co2 were highly spin-polarized with local magnetic moments of 3 and 2μB.

关键词： magnetism 3d transition metal dimer ab initio calculation

Thermal stability of nanograins with grain boundary relaxation in microalloyed Cu-Sb and Cu-Fe

在线全文

学校读者我要写书评

暂无评论

journal of Materials Science & Technology 2023年第24期155卷 66-71页

作者： R.j. zhu X.Zhou X.Y. Li Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China School of Materials Science and Engineering University of Science and Technology of China Shenyang 110016 China

Grain refinement into nanoscale significantly enhances the strength and hardness of metallic materials but generally reduces the thermal stability by the introduced strong tendency for grain boundary(GB)*** nanograins through GB relaxation had been proven as an effective way in several metals recently when the grain size is below a critical ***,we discovered that the abnormally enhanced thermal stability induced by GB relaxation can be realized in 0.5%Sb or Fe doped Cu,similar to that in pure *** observed critical grain sizes for GB relaxation in the two Cu alloys are almost the same as pure ***,the GB relaxation effect on thermal stability is kind of suppressed compared to pure Cu with similar grain sizes because of the segregation/precipitation of Sb/Fe during the annealing process,which accelerates the detwinning and the failure of relaxed GBs.

关键词： Thermal stability Grain boundary relaxation Nanograined Cu alloy Segregation Precipitate

Effect of intermittent aeration mode on nitrogen concentration in the water column and sediment pore water of aquaculture ponds

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Environmental Sciences 2020年第4期32卷 331-342页

作者： Dantong zhu Xiangju Cheng David j.Sample Mohammad Nayeb Yazdi State Key Laboratory of Subtropical Building Science South China University of TechnologyGuangzhou 510640China School of Civil Engineering and Transportation South China University of TechnologyGuangzhou 510640China Department of Biological System Engineering Virginia Polytechnic Institute and State UniversityVirginia Beach 23455United States

Nitrogen in pond sediments is a major water quality concern and can impact the productivity of *** oxygen is an important factor for improving water quality and boosting fish growth in aquaculture ponds,and plays an important role in the conversion of ammonium-nitrogen(NH4-N)to nitrite-nitrogen(NO2--N)and eventually nitrate-nitrogen(NO3--N).A central goal of the study was to identify the best aeration method and strategy for improving water quality in aquaculture *** conducted an experiment with six tanks,each with a different aeration mode to simulate the behavior of aquaculture *** results show that a 36 hr aeration interval(Tc=36 hr:36 hr)and no aeration resulted in high concentrations of NH4-N in the water *** a 12 hr interval time(Tc=12 hr:12 hr)resulted in higher NO2--N and NO3--N concentrations than any other aeration *** from an 8 hr interval time(Tc=8 hr:8 hr)and 24 hr interval time(Tc=24 hr:24 hr)were comparable with those of continuous aeration,and had the benefit of being in use for only half of the time,consequently reducing energy consumption.

关键词： Intermittent aeration Nitrogen Water column Sediment resuspension and release Sediment Sediment pore water

Engineered polymer nanoparticles incorporating L-amino acid groups as affinity reagents for fibrinogen

在线全文

学校读者我要写书评

暂无评论

journal of Pharmaceutical Analysis 2021年第5期11卷 596-602页

作者： Yongyan zhu Ruixuan Liu Dengyu Wu Qianqian Yu Kenneth j.Shea Quanhong zhu School of Traditional Chinese Medicine Southern Medical UniversityGuangzhou510515China Guangdong Provincial Key Laboratory of Chinese Medicine Pharmaceutics Guangzhou510515China Guangdong Provincial Engineering Laboratory of Chinese Medicine Preparation Technology Guangzhou510515China Department of Chemistry University of CaliforniaIrvineCA92697USA

Synthetic polymer hydrogel nanoparticles(NPs)were developed to function as abiotic affinity reagents for *** NPs were made using both temperature-sensitive N-isopropyl acrylamide(NIPAm)and L-amino acid *** kinds of L-amino acids were acryloylated to obtain functional monomers:L-phenylalanine(Phe)and L-leucine(Leu)with hydrophobic side chains,L-glutamic acid(Glu)with negative charges,and L-lysine(Lys)and L-arginine(Arg)with positive *** incubating the NPs with fibrinogen,g-globulin,and human serum albumin(HSA)respectively,the NPs that incorporated Nacryloyl-Arg monomers(AArg@NPs)showed the strongest and most specific binding affinity to fibrinogen,when compared with g-globulin and ***,the fibrinogen-AArg binding model had the best docking scores,and this may be due to the interaction of positively charged AArg@NPs and the negatively charged fibrinogen D domain and the hydrophobic interaction between *** specific adsorption of AArg@NPs to fibrinogen was also confirmed by the immunoprecipitation assay,as the AArg@NPs selectively trapped the fibrinogen from a human plasma protein ***@NPs had a strong selectivity for,and specificity to,fibrinogen and may be developed as a potential human fibrinogen-specific affinity reagent.

关键词： Synthetic polymer nanoparticles Amino-acid monomers Arginine Fibrinogen Affinity reagent Protein interaction

Variation and mechanisms of clastic reservoir quality in the Paleogene Shahejie Formation of the Dongying Sag, Bohai Bay Basin, China

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2014年第2期11卷 200-210页

作者： Zhang Qin zhu Xiaomin Ronald j Steel Zhong Dakang College of Geosciences China University of Petroleum State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum Department of Geological Sciences The University of Texas at Austin

Reservoir quality varies greatly in the Shahejie Formation in the Dongying Sag. It is essential to analyze the variation and mechanisms of reservoir quality for determining the controlling factors based on cores, porosity measurements and fluid inclusion techniques and so on. The sandstones in the fluvial, （fan） delta-front have the best reservoir quality due to the depositional conditions mechanically controlling the petrology configuration and the primary porosity, and chemically influencing the diagenesis and development of secondary pores. The activity of the boundary faults and the sedimentary facies dominate the variation of reservoir quality in different areas and intervals. The reservoir quality varies with the position of sandstone beds in different vertical models of sandstone and mudstone. This mainly arose from the strong cementation or strong dissolution in the sandstone caused by the diagenesis evolution of adjacent mudstone. With higher oil saturation reservoir quality is better because the hydrocarbon charge favors dissolution and restricts cementation. Diagenesis, depositional conditions and tectonic setting are the key controls of reservoir quality in the Shahejie Formation of the Dongying Sag.

关键词： Reservoir quality variation clastic reservoir quality hydrocarbon charge vertical models ofsandstone and mudstone controlling factor